Features of the normal choriocapillaris with OCT-angiography: Density estimation and textural properties

The main objective of our work is to perform an in depth analysis of the structural features of normal choriocapillaris imaged with OCT Angiography. Specifically, we provide an optimal radius for a circular Region of Interest (ROI) to obtain a stable estimate of the subfoveal choriocapillaris density and characterize its textural properties using Markov Random Fields. On each binarized image of the choriocapillaris OCT Angiography we performed simulated measurements of the subfoveal choriocapillaris densities with circular Regions of Interest (ROIs) of different radii and with small random displacements from the center of the Foveal Avascular Zone (FAZ). We then calculated the variability of the density measure with different ROI radii. We then characterized the textural features of choriocapillaris binary images by estimating the parameters of an Ising model. For each image we calculated the Optimal Radius (OR) as the minimum ROI radius required to obtain a standard deviation in the simulation below 0.01. The density measured with the individual OR was 0.52 ± 0.07 (mean ± STD). Similar density values (0.51 ± 0.07) were obtained using a fixed ROI radius of 450 μm. The Ising model yielded two parameter estimates (β = 0.34 ± 0.03; γ = 0.003 ± 0.012; mean ± STD), characterizing pixel clustering and white pixel density respectively. Using the estimated parameters to synthetize new random textures via simulation we obtained a good reproduction of the original choriocapillaris structural features and density. In conclusion, we developed an extensive characterization of the normal subfoveal choriocapillaris that might be used for flow analysis and applied to the investigation pathological alterations

Wystepowanie pasozytow czlowieka w wybranych populacjach na przykladzie badan przeprowadzonych w Slaskiej Wojewodzkiej Stacji Sanitarno-Epidemiologicznej

Frequency of human parasites in selected populations of Silesian region. Epidemiological evaluation of the most frequent human parasitoses in the group of children at age of seven years, in adult patients and in group of Polish citizens coming back from tropics between 1999-2003 was performed. All examined people were Silesian region inhabitants. The biggest average infection prevalence in children from all examined years concerned Enterobius vermicularis, in adult - Giardia intestinalis, while in group of population coming back from tropics - Entamoeba histolytica-like. High percentage of anti-Toxocara canis and Toxoplasma gondii antibodies presence can result from non randomly study group recruitment

Blood flow measurement and slow flow detection in retinal vessels with Joint Spectral and Time domain method in ultrahigh speed OCT

We present an application of the Joint Spectral and Time domain OCT (STdOCT) method for detection of wide range of flows in the retinal vessels. We utilized spectral/Fourier domain OCT (SOCT) technique for development of scan protocols for Doppler signal analysis. We performed retinal imaging in normal eyes using ultrahigh speed (200 000 axial scans/s) SOCT instrument with a CMOS camera. Various raster scan protocols were implemented for investigation of blood flow in the retina. Data analysis was performed using the method of joint Spectral and Time domain OCT (STdOCT). Detection of blood flow velocities ranging from several tens of mm/s to a fraction of mm/s was possible with scanning methods allowing for appropriate selection of time intervals between data taken for Doppler OCT analysis. Axial blood flow velocity measurement was possible in retinal vessels. Doppler OCT signal can be utilized as a contrast mechanism for visualization of retinal capillaries.Poland. Ministry of Science and Higher Education (Grant Number 2076/B/H03/2009/37

Regulated anion secretion in cultured epithelia from Sertoli cells of immature rats

Cultured epithelia of Sertoli cells from prepubertal rats were grown on Matrigel-coated millipore filters for short-circuit current (Isc) measurements. Under basal conditions, these epithelia exhibited a ‘zero’ transepithelial potential difference, a ‘zero’ short-circuit current and a transepithelial resistance of 60 Ω cm2.Forskolin (100 μm) and 8-(4-chlorophenylthio)-cAMP (cpt-cAMP) (100 μm) added to the apical side stimulated the Isc (forskolin, peak ΔIsc = 1.32 ± 0.16 μA cm−1; cpt-cAMP, peak ΔIsc = 0.88 ± 0.16 μA cm−2).ATP (100 μm) added apically elicited a Isc response (peak ΔIsc = 6.45 ± 0.28 μA cm−2) which was similar in magnitude to that of 1 μm thapsigargin (peak ΔIsc = 6.09 ± 0.44 μA cm−2). The potency of the responses to other nucleotides: UTP ≥ ATP > ADP >> AMP = adenosine indicates the involvement of a mixture of P2Y receptors.Removal of extracellular Cl− and HCO3− reduced the Isc response to ATP by 70% and 40%, respectively. Removal of K+ had no effect, whereas removal of Na+ attenuated the Isc response.The response to ATP was insensitive to agents known to block anion secretion (except apical diphenylamine-2-carboxylate (DPC) and DIDS). The resistance to perturbation by pharmacological agents may be a unique property of the seminiferous epithelium.Whole-cell current recordings in cultured rat Sertoli cells demonstrated a DIDS-sensitive outwardly rectifying Cl− conductance with activating and inactivating characteristics at depolarizing and hyperpolarizing voltages, respectively.The stimulation of electrogenic ion transport by ATP may be part of a complex mechanism regulating fluid secretion by the testis. Cultured Sertoli cell epithelia are shown to provide a useful model to investigate transepithelial transport in the seminiferous epithelium